test/event: fix build with clang 15

[ upstream commit ff5b90f9d0675f1fa92b449ed086b6641301be51 ]

This variable is not used.

Fixes: d1f3385 ("test: add event timer adapter auto-test")

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Tested-by: Daxue Gao <daxuex.gao@intel.com>

app/test/test_event_timer_adapter.c

@@ -764,7 +764,6 @@ _cancel_thread(void *args)
 {
 	RTE_SET_USED(args);
 	struct rte_event_timer *ev_tim = NULL;
-	uint64_t cancel_count = 0;
 	uint16_t ret;
 
 	while (!arm_done || rte_ring_count(timer_producer_ring) > 0) {
@@ -774,7 +773,6 @@ _cancel_thread(void *args)
 		ret = rte_event_timer_cancel_burst(timdev, &ev_tim, 1);
 		TEST_ASSERT_EQUAL(ret, 1, "Failed to cancel timer");
 		rte_mempool_put(eventdev_test_mempool, (void *)ev_tim);
-		cancel_count++;
 	}
 
 	return TEST_SUCCESS;